Campylobacter C Jejuni and C coli have emerged

Campylobacter: C. Jejuni and C. coli have emerged as common human pathogens, causing mainly enteritis and occasionally systemic diseases. Morphology: Small Gram negative bacilli, with comma or S shape. They are motile with single unsheathed polar flagellum, at one or both poles.

Culture characters: • They are microaerophilic, best growth at 42⁰C in atmosphere containing 5% O₂ & 10% CO₂. They grow on a selective medium called Skirrow’s medium (containing lysed blood agar and vancomycin, polymyxin & trimethoprim). Method of transmission: • Usually, fecal-oral. Domestic animals such as cattle, chicken and dogs serve as a source of infection. Food and water contaminated with animal feces are the major source of human infection

Pathogenesis: • C. jejuni is an invasive and toxogenic organism. It produce two exotoxins; enterotoxin and cytotoxin. Clinical picture: • Incubation period 3 days • Symptoms are severeng abdominal pain, nausea and diarrhea. Leucocytes are almost present in the feces, and frank blood may be apparent • Symptoms usually resolve within few days, but excretion of bacteria may continue for several weeks.

• Complications Ascptic arthritis or peripheral polyneuropathy (Guillain Barre’ syndrome; antibodies cross react with the myelin in nerve sheaths lead to symmetrical weakness). Laboratory diagnosis: • A stool specimen is cultured on Skirrow’s medium and incubated at 42⁰C in a microacrophilic atmosphere (5% O₂) containing 10% CO₂. The organism is defined by failure to grow at 25 C, oxidase positive and catalase positive and sensitivity to antibiotics.

• Serology can he useful in patients presenting with aseptic arthritis or Guillain-Barre’ syndrome after about of diarrhea, Complement fixation test and ELISA tests can detect recent infection with C. jejuni and C. coli. Treatment: • Erythromycin, nalidixic acid and tetracyclines. Partially sensitive to ampicellin.